實時測試的速度：
--48466條資料
--1.297
inline view更新法
inline view更新法就是更新乙個臨時建立的檢視
update (select a.join_stateas join_state_a,b.join_stateas join_state_b
from t_join_situation a, t_people_info b where a.people_number=b.people_number
and a.year='2011' and a.city_number='m00000' and a.town_number='m51000'
) set join_state_a=join_state_b
括號裡通過關聯兩表建立乙個檢視，set中設定好更新的字段。這個解決方法比寫法較直觀且執行速度快。但表b的主鍵一定要在where條件中，並且是以「=」來關聯被更新表，否則報錯誤
--7.156
update t_join_situation aset a.join_state=(select b.join_statefrom t_people_info b
where a.people_number=b.people_number
and a.year='2011' and a.city_number='m00000' and a.town_number='m51000')
where exists (select 1 from t_people_info b
where a.people_number=b.people_number
and a.year='2011' and a.city_number='m00000' and a.town_number='m51000')
--3.281
begin
for crin (select a.rowid,b.join_statefrom t_join_situation a,t_people_info b
where a.people_number=b.people_number
and a.year='2011' and a.city_number='m00000' and a.town_number='m51000')loop
update t_join_situationset join_state=cr.join_statewhere
rowid = cr.rowid;
end loop;
end;
--1.641
merge into t_join_situation a
using t_people_info b
on (a.people_number=b.people_number
and a.year='2011' and a.city_number='m00000' and a.town_number='m51000')
when matched then update set a.join_state=b.join_state
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